The present invention relates generally to digital cellular communication, and more particularly to non-GSM signaling in a general packet service based GSM network.
A General Packet Radio Service (xe2x80x9cGPRSxe2x80x9d) is a packet data service used by Global System for Mobile Communication (xe2x80x9cGSMxe2x80x9d) networks to enable the GSM networks to send and receive data in an end-to-end packet transfer mode. As a result, network architecture used in a GSM network to support packet data service includes two pure packet network nodes. These pure packet network nodes include a Serving GPRS Support Node (xe2x80x9cSGSNxe2x80x9d) that is used to perform signaling operations, along with a Gateway GPRS Support Node (xe2x80x9cGGSNxe2x80x9d) used to interface with an internet protocol (xe2x80x9cIPxe2x80x9d) network. The SGSN can also be connected to other SGSNs belonging to other service providers, which in turn can also be connected to other SGSNs, and so forth.
FIG. 1 is a schematic diagram of a packet data service based GSM network. As illustrated in FIG. 1, in addition to a SGSN 22 and a GGSN 24, a GPRS based GSM network 20 generally includes a mobile station 26 interconnected with a base station 28 that in turn interfaces with the SGSN 22, a mobile switching center (xe2x80x9cMSCxe2x80x9d) 30, and a home location register (xe2x80x9cHLRxe2x80x9d) 32 associated with the mobile switching center 30 that is used to authenticate service.
The base station 28 receives a message sent by the mobile station 26 and the message is transmitted from the base station 28 to the SGSN 22. The SGSN 22 terminates the message, processes information associated with the message to generate new signaling, and transmits the new signaling to the mobile switching center 30. In the same way, a message to be sent by the mobile switching center 30 to the mobile station 26 is transmitted from the mobile switching center 30 to the SGSN 22. The SGSN 22 terminates the message, processes information associated with the message to generate new signaling, and transmits the new signaling to the mobile station 26 through the base station 28.
In a network system in which both the mobile switching center 30 and the SGSN 22 operate using GSM based technology, this process of terminating the message and processing information to generate new signaling that is performed by the SGSN 22 involves processing of information using a single technology, namely GSM technology. As a result, the termination of the message and the generation of new signaling by the SGSN 22 can be accomplished without requiring significant modification to the SGSN 22.
However, operation of different, non-GSM related technologies within the framework of the GPRS based GSM network elements, i.e., the SGSN 22 and the GGSN 24, requires that technologies different from the GSM technology be included in the GSM network 20. For example, when the mobile switching center 30 is designed to operate within the framework of a non-GSM network, the mobile switching center 30 utilizes technologies other than GSM technologies, and therefore the mobile switching center 30 must operate using a technology substantially different from that of the SGSN 22 in order to provide packet services to the mobile station 26. Since the mobile station 26 can only be reached through the SGSN 22, the SGSN 22 would be required to process information using both GSM and the non-GSM technology. As a result, connecting the non-GSM mobile switching center with the SGSN 22 becomes more complicated and requires significant modifications of the SGSN 22 and the non-GSM mobile switching center, limiting the extent of signaling and non-signaling messages that can be exchanged between the mobile station 26 and the non-GSM mobile switching center.
Therefore, what is needed is a procedure that minimizes necessary changes to the SGSN 22 and the non-GSM mobile switching center, while enabling deployment of a wide variety of signaling and non-signaling message exchanges between the mobile station 26 and the mobile switching center 30, that has minimal effects upon the operation of the SGSN 22.